Modem Fails to Disconnect After Selecting Hang Up in RASPHONE (127881)


The information in this article applies to:

  • Microsoft Windows NT Server 3.1
  • Microsoft Windows NT Workstation 3.1
  • Microsoft Windows NT Advanced Server 3.1
  • Microsoft Windows NT Workstation 3.5
  • Microsoft Windows NT Workstation 4.0
  • Microsoft Windows NT Server 3.5
  • Microsoft Windows NT Server 4.0
This article was previously published under Q127881

SUMMARY

Your modem may fail to disconnect from a remote modem when you choose the Hang Up button in Windows NT Remote Access (RASPHONE.EXE). RASPHONE acts as if the connection is broken, however, your modem is still connected to the remote modem. When you select the Hang Up button in RASPHONE, Remote Access Service (RAS) drops Data Terminal Ready (DTR) to force the modem to disconnect from the remote modem.

MORE INFORMATION

If your modem is not disconnecting from the remote modem after you select the Hang Up button in RASPHONE:

  1. Check your modem cable if your are using an external modem.

    • Verify that your RS-232 modem cable includes a DTR pin.
    • Many 9-to-25 pin converters do not carry modem signals (including DTR).
    • Try using a different cable that you know is working correctly with RAS.
    • See the RAS help file (RASPHONE.HLP) for additional information on cable requirements for RAS.
  2. Verify that RAS is setting your modem to use normal DTR operations. Most modems use the &D2 command to set the modem for normal DTR operations. To determine if normal DTR operations are being set properly for your modem, check the COMMAND_INIT string in it's corresponding section of the Windows NT MODEM.INF file. See the RAS help file for additional information on viewing and modifying the MODEM.INF file.
  3. Confirm that your modem is not configured to ignore DTR. Some modems include a dip switch or jumper that allows you to configure the modem to ignore DTR. Check your modem documentation for information on how to configure your modem to use normal DTR operations or ignore DTR.
  4. Add the following setting to the COMMAND_INIT string for your modem in the MODEM.INF file:

    S25=3.

    S25 controls the duration of time (in hundredths of a second) that DTR must be dropped before the modem disconnects itself from the remote modem. Setting this value to 3 will ensure that the modem disconnects almost immediately after choosing the Hang Up button in RASPHONE.
Modification Type:MajorLast Reviewed:5/6/2003
Keywords:kbnetwork KB127881
©2002 Microsoft Corporation. All rights reserved.